This invention relates to a reactor for gasifying solid fuels, particularly coal, in a packed bed by a treatment with gasifying agents comprising free oxygen-containing gases and water vapor, under a pressure of 5-100 bars, comprising a water-cooled reactor housing, a fuel distributor which is rotatable on a vertical axis, a rotatable stirrer, which is disposed in the fuel bed in the upper portion of the reactor, and gasifying agent inlet openings in the lower portions of the reactor.
Reactors for the pressure gasification of solid fuels, such as coal, brown coal or also peat are already known. Details of these pressure reactors are explained in Printed German Application 1,021,116 and German Patent 2,352,900 and U.S. Pat. Nos. 2,667,409; 3,930,811; 3,902,872; and 3,937,620, the disclosures of which are incorporated herein by reference. In the known reactor and in the reactor according the invention, granular fuel forming a packed bed descends under gravity and is contacted and reacted with gasifying agents flowing in a countercurrent. In addition to water vapor and oxygen, the gasifying agents may comprise oxygen-containing or oxygen-releasing gases, such as air or carbon dioxide.
Efforts are being made to provide reactors for the pressure gasification of fuels at progressively increasing throughput rates and to enable the gasification also of caking and swelling coals. In known reactors these efforts have been obstructed by difficulties due to a nonuniform gasification behavior. It is an object of the invention to eliminate the difficulties which have arisen in the state of the art and to ensure a uniform gasification also of caking and swelling coals. In a reactor of the kind defined herein above this is accomplished according to the invention in that the stirrer and distributor are adapted to be rotated independently of each other by first and second drive means, respectively.
In the previously known reactors, the stirrer and the distributor are rigidly interconnected. In view of the requirements previously to be met in connection with the pressure gasification of solid fuels, this arrangement has given quite satisfactory results. Surprisingly it has been found, however, that the elimination of the coupling between the distributor and stirrer permits a more flexible operation under adjustable conditions and that this is sufficient to preclude certain troubles which arise in known reactors. In view of the state of the art it was unexpected that the measures adopted according to the invention would result in substantial improvement.